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[英]How to return byte array as an in memory file in java spring boot?
[英]How does spring boot return byte stream in real time like PHP's readfile function?
我正在解决一个需求。 我正在使用 springboot 框架。 现在有一个接口,传入参数url。 这个url是一个网络文件地址。 接口收到请求后,使用自己的网络请求网络文件,并实时返回给客户端。 ,php的readfile函数可以解决问题,但是java语言有没有这样的解决方法呢? 我需要的是实时返回给客户端,而不是读取全部返回给客户端
@Controller
@Api(tags = "test")
@RequestMapping("/test")
@CrossOrigin
public class TestController {
@RequestMapping(value = "/get", method = RequestMethod.POST)
@ApiOperation(value = "get")
public ResponseEntity<FileSystemResource> test() throws IOException {
OkHttpClient client = new OkHttpClient().newBuilder()
.build();
MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{\"123\": 1}");
Request request = new Request.Builder()
.url("https://github.com/xujimu/ios_super_sign/archive/refs/heads/master.zip")
.method("GET", body)
.addHeader("Content-Type", "application/json")
.build();
Response response = client.newCall(request).execute();
}
}
您可以为此使用ResponseEntity<StreamingResponseBody>
。
您已选择要返回的内容类型。 我们最终得到了produces = MediaType.APPLICATION_NDJSON_VALUE
。
我们必须通过将RestClient to
更改为 WebClient 来修改我们执行休息请求的方式:
Flux<DataBuffer> dataStream = return webClient.method(method)
.uri(url)
.retrieve()
.bodyToFlux(DataBuffer.class);
DataBufferUtils.write(dataStream, response.getOutputStream())
.map(DataBufferUtils::release)
.blockLast();
当我们终于让它工作时,它真的很好用:)
您可以在https://www.baeldung.com/spring-mvc-sse-streams上看到一些其他示例。
我通过java的URL类解决了这个问题
package com.api.controller;
import cn.dev33.satoken.annotation.SaCheckLogin;
import cn.dev33.satoken.stp.StpUtil;
import com.api.common.result.PageReq;
import com.api.common.result.PageResult;
import com.api.common.result.Result;
import com.api.common.user.AddBalanceReq;
import com.api.constant.ResultCode;
import com.api.dao.ApiUserDao;
import com.api.dao.UserFlowDao;
import com.api.entity.ApiUserEntity;
import com.api.entity.UserFlowEntity;
import com.api.execption.ResRunException;
import com.api.service.ApiUserService;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.InputStreamResource;
import org.springframework.core.io.Resource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
import reactor.core.publisher.Flux;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.DataBuffer;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Date;
@Controller
@Api(tags = "test")
@RequestMapping("/test")
@CrossOrigin
public class TestController {
/**
* 添加用户月
*
* @param req
* @return
*/
@RequestMapping(value = "/get", method = RequestMethod.GET)
@ApiOperation(value = "get")
public void test(String url, HttpServletResponse response) throws IOException {
URL url1 = new URL(url);
InputStream is = url1.openStream();
int ch;
while ((ch = is.read()) != -1) {
response.getWriter().write(ch);
}
}
}
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